ncdfCF 0.2.1

ncdfCF 0.2.0

• NetCDF groups are now fully supported, including traversing group hierarchies with absolute or relative paths.
• All axis types are identified correctly. This includes:
  • Regular coordinate axes (a.k.a. NUG coordinate variables).
  • Discrete axes, even when no coordinate variable is present - an extension to the CF conventions.
  • Parametric vertical axes, but values are not yet computed.
  • Scalar axes, linked to variables through the “coordinates” attribute of the latter.
  • Auxiliary longitude-latitude grids, the horizontal component of the grid of a variable that was not defined as a Cartesian product of latitude and longitude, using the “coordinates” attribute of the variable. When subsetting a data variable, resampling is automatically performed.
  • The four axes that “receive special treatment” by the Conventions each have a separate class to deal with their specific nature: CFAxisLongitude, CFAxisLatitude, CFAxisVertical, and CFAxisTime.
• Bounds are read and interpreted on all axes except the vertical axis, including any auxiliary long-lat grids.
• Information on UDTs is captured in a separate class. This is effectively only supported for the “compound” sub-type, for scalar values only.
• Data is read into the most compact form possible. This saves a significant amount of memory when large integer variables are read as they would remain integers rather than the default numeric type.
• Data is returned from CFVariable$subset() as an instance of the CFData class, with associated objects such as axes and the attributes from the variable. Data can be read out in a variety of forms, currently as a raw array, an oriented array or as a terra::SpatRaster or terra::SpatRasterDataset.
• Full support for grid mapping variables. As a significant extension over CF Metadata requirements, CRS strings are produced in the OGC WKT2 format, using the latest EPSG database of geodetic objects.
• Improvements in printing object details.
• Code refactored to R6.
• GHA enabled

ncdfCF 0.1.1

• objects_by_standard_name() will list objects in the netCDF resource that have a “standard_name” attribute.

ncdfCF 0.1.0

• Initial CRAN submission. This is a WORK IN PROGRESS and the package is not yet fit for a production environment.
• This version supports reading from netCDF resources. CF Metadata Conventions are used to set properties on axis orientation, time dimensions and bounds.
• Standard R commands can be used to inspect properties of the netCDF resource, such as dimnames() and length().
• Access to data uses the R standard [ selection operator for use with dimension indices. Use real-world coordinates with subset().